public ParameterExpression(int modifier, Type type, String name) {

    super(ExpressionType.Parameter, type);

    assert name != null : "name should not be null";

    assert Character.isJavaIdentifierStart(name.charAt(0))

      : "parameter name should be valid java identifier: "

        + name + ". The first character is invalid.";

    this.modifier = modifier;

    this.name = name;

  }